Rivet manufacture.



N. E. CLARK.

RIVET MANUFACTURE.

APPLICATION FILED NOV. '1, 1911.

LQM Q88D Patented 5331.21, 1913.

Fig: 1- Fig: 2- 19 Fig- 3- 27 l O H u Q s Q I k\\\\\\\\\\ F g 6 F1 1 5ig- 6- I! WITNESSES 37 INVENTOR 2f? NWI'S lma flaw-k, 1 zzzr A NGRRISnraaonn CLARK, or PLAINVILLE, connno'riou'r.

RIVET MANUFACTURE.

Specification of Letters Patent.

Patented Jan. 21, 191$.

Application filed Hovember 7, 1911. Serial No. 658,936.

To all whom/ it may concern:

Be it known that L NoRRIs ELMoRn CLARK, a citizen of the United States,and resident of Plainville, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements in RivetManufacture, of which the following is a specification.

My invention relates particularly to :1 process and tools formanufacturing rivets and similar devices.

The right to claim the mechanism is reserved for another application.

The main object is to provide a simple process and the means fgr makingrivets cupped at one end so that they may be readily and uniformlyup-sct. The principle will be found also applicable to the manufactureof bifurcated and tubular rivets.

Briefly considered, the invention contemplates the forcing of a rivetblank into a hole in a die, indenting and thereby spreading the endinside-the die by means of a movable pointed punch, then forcing therivet out of the die by means of the punch so that the spread end of therivet inside the die is drawn out to form the cupped portion. Where thecupped portion is deep su plementary vmechanism may be provide fortaking off or ejecting the completed rivet from the die.

The principles of the invention are illustrated in the accompanyingsingle sheet of drawings.

Figure 1, is a side view of a blank for forming a rivet. Fig. 2, is alongitudinal sectional view showing the rivet with the end indented andspread in accordance with a step of my invention and showing dotted thecompleted end. Fig. 3,i's a perspective view of a completed rivet of myinvention.-

Fig. 4, is a side view and partial section of apparatus for carrying outmy invention. Fig. 5, is a longitudinal sectional view of forming diesshowing the end of the rivet indented and spread. Fig. 6, is a similarview of a modification with a punch suitable for making a square orrectangular countersink. Fig. 7 shows an end view and a side view of thes ecial punch shown in Fig. 6 for forming a rivet suchas a clockkeyrivet or stem having a square recess in p the end as shown in Fig. 8.Fig. 9, shows an en and a side view of another form of punch with awedge-shaped end for forming a bifurcated rivet as shown in Fig. 10.Fig. 11, is a sectional view of another form of rivet which maybe madeaccording to my lnvention. I

As the tools may be operated in any suitable form of rivet machine orheader Ihave only attempted to illustrate those parts carry' or transferthe blank 5 into position in front of the die 6 in line with the opening7. A completed rivet is shown at 8. A. header 9 carried by the movablemember or gate 10 is operated in the usual manner to drive the blank 5into the die 6 and head or up-set a portion of the rivet as iscustomary.

The shape of the head will of course depend upon the shape ofthe headingrecess in the die 9. v

The die 6 is provided with a recess 11 of a size larger than the passage7 so as to permit the end of the rivet to spread as shown in Fig. 5.Preferably this recess is open at the bottom to permit scrap, etc., tofall out. The knock-out pin 12 constitutes a movable abutment or punchand has its end 13 shaped in accordance with the de-- sired shape of thecavity to be formed in the end of therivet. When the rivet blank isforced into the opening 7 the right hand end isindented and spread bythe end 13 of the movable punch 12 as shown at 14. An arm 15 or similardevice is provided for moving the knockout pin or {punch toward the leftand a suitable form 0 spring 16- assists in retracting the knock-out pinor punch, In Fig. 5 a spiral spring 16 is shown for the same purpose.This figure also shows a separate sleeve 17 in the rear of the die 6 forguiding the knock-out pin or punch.

When the-knock-out pin or punch 12 is forced to the left the rivet 8 isejected through passa e 7. The ri ht hand end 14 of the rivet icingsprea is drawn out around the end 13 of the knock-out pin or punch inbeing forced back through the passage 7. A separate bushin '18 may beconveniently provided for afi'or mg a drawing shoulder around the mnerend of the passage 7, the edge of the passage in the bushing beingrounded as'shown m Fig. 5 so as to secure a better drawing action andavoid any shearing action. By this drawing action the spread portion 14is drawn out into a tubular form as shown at 19 in Fig. 3 and dottedinFig. 2. The drawing action will depend upon the relative size of thepassage in' the drawing die and the p o1nt of the punch and also theforce .apphed to the punch. By exercising considerable force upon thepunch and having the end 13 of a size less in diameter than the diameterof the rivet as shown for instance in Fig. 6 a very considerable drawingaction may be pro duced. The drawing action and cavity will of coursedepend somewhat upon the char- .acteristics of the metal of the rivet orother device. By shaping the end of the punch square and pointed asshown in Fig. 7 it is possible to produce by this method a clockkeyrivet having a square recess as shown at 22 in Fig. 8.

Sometimes there is a tendency for the rivets to stick in the die '6 oron the end of the punch. In' this case additional means should beemployed to properly eject the rivet as shown for instance in Fig.- 4. Aforked-like kicker 23 is plvotally hinged from an arm of the lever 24which is pivoted at 25. A spring 26 presses the kicker toward the rightas shown in Fig. 4. The upright arm of the lever 24 is connected by arod 27 to the upright bracket 28 on a movable sup ort 10 for the header9. The rod 27 may lie extensible in any suitable manner as for instance,by a suit-able form of coupling 29 so that the length of the rod may bead'usted. A stationary cam 30 1s provided adjacent the cam 31 on thekicker 23. When the header 9 and carrier 10 are bein retracted thekicker 23 is moved downwar and outward so as to eject the finished InFig. 11 I have shown another form of I rivet 37 which may be formedaccording to my invention. The left hand end represents that portion ofthe rivet which is formed by the header punch If such a countersink wereattempted in connection with the usual die, the outward flow of thestock within the punch would cause the rivet to stick in the punchpreventing a propenoperation of the heading machine. But with my form ofdie owmg to the greater outward flow of stock within the die than withinthe punch,

the grivetalways stays in the die until knocked out by the knock-out pinor punch 12.

What I claim is 2-- 1. In the art of forming rivets the improvementwhich consists in forming a conical indentation in one end of a blankand .spreading the end around the indentation and then drawing out thespread portion.

2. The improvement in the art of forming rivets which comprisessimultaneously forming a head on one end of a blank and indenting andspreading the opposite end and then drawing out the periphery of thespread end.

3. The improvement in the art of forming rivets 'which comprisesindenting and spreading one end by a punch and then forcing the spreadend through a die so as to draw out the periphery around the end of thepunch.

NORRIS ELMORE CLARK.

Witnesses:

L. F. C. CLARK, L. G. ALLY'N.

